Device for centralizing strip material



Aug. 23, 1949. MacPHEAT DEVICE FOR CENTRALIZING STRIP MATERIAL FiledSept. 9, 194-7 Patented Aug. 23, 194

DEVICE FOR CENTRALIZING STRIP MATERIAL Alexander M. MacPheat,Brookfield,

Ill., assignor to Western Electric Company, Incorporated, New York, N.Y., a corporation of New York Application September 9, 1947, Serial No.772,956-

7 Claims.

This invention relates to a device for centralizing a strip material andmore particularly to a centering device applicable to a punch press forcentering strip material on a predetermined center line in the punchpress in response to the downstroke of" the ram of the press.

It is an object of the present invention to provide a centralizingdevice of simple construction for centralizing strip material relativeto a predetermined center line.

In one embodiment of the invention as applied to a punch press having adie and a plurality of punches for punching the strip material intocontact springs having a plurality of perforations on its longitudinalcenter line, there is provided a pair of centralizing devices on the diein spaced relation to each other, each comprising a cylindrical membermounted for rotation about an axis located on the predetermined centerline. A pair of rollers are mounted on the lower side of eachcylindrical member diametrically opposite and equi-distant from the axisof the cylindrical member and spaced apart a distance greater than thewidth of the strip material to receive the strip material therebetween.The upper surface of each cylindrical member is provided with camsurfaces which are engageable with cooperating actuating cam membersyieldingly mounted on the punch holder for reciprocatory movementtherewith predetermined point in the downward movement of the ram of thepress, the cooperating cam members will engage the cam surfaces on thecylindrical members and cause the cylindrical members to rotate andthereby, urge the rollers thereon simultaneously in opposite directionstoward the center line into engagement with the opposite edges of thestrip to centralize the strip.

The invention will be more fully understood by reference to thefollowing detailed description thereof and the accompanying drawingsillustrating a preferred embodiment of the invention, wherein Fig. 1 isa fragmentary plan View of the lower portion of a punch and diemechanism with the centralizing device therein;

Fig. 2 is a vertical sectional view through the punch and die mechanismshowing the die in its lower or operative position and taken on the line2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view through a portion of the stripequalizing mechanism taken on the line 3-3 of Fig. 1; and

Fig. 4 is a detailed bottom plan view of one of the centralizingmembers.

whereby, at a In the processing of strip material with the aid of apunch press wherein a plurality of perforations are formed in the stripand the strip out into predetermined lengths to form contact springs forelectrical relays, it is important that the perforations be locatedaccurately along the center line of the strip. Due to the slightvariations in the overall width of the strip material, it is necessaryto centralize the strip relative to a predetermined center line passingthrough the axis of the perforating punches.

In the drawings illustrating one embodiment of the invention applied toa punch and die mechanism for forming contact springs from stripmaterial, the strip material In is fed over a die 12 mounted on a dieholder l3, which, in turn, is secured to a bolster plate 14 of a punchpress. The die block 12 is provided with punch apertures l5 formingcutting edges which cooperate with a pair of punches is to formperforations on the longitudinal center line of the strip In. Thepunches l6 are secured by a retaining plate I! to a punch holder l8which, in turn, is mounted on a ram l9 of a punch press forreciprocation therewith. A stationary stripper plate 22 is secured tothe die block l2 and is provided with a longitudinal slot or passageway23 for loosely receiving and guiding the strip H).

The strip It] may be advanced manually or by suitable feeding mechanismuntil the forward edge engages the stop surface 25 of a stop member 26secured to the die holder for stopping the strip in a predeterminedposition relative to the punch and die. A curved cutting edge 28 isformed on the left hand end of the die block it as viewed in Fig. l anda straight cutting edge 29, in spaced relation to the cutting edge 28,is formed on a die block 30 mounted on the die holder l3. The cuttingedges 28 and 29 cooperate with similar cutting edges formed on the punch33 secured to the punch holder l8 for reciprocation therewith to punchout a slug or blank from the strip l0, thus to sever a completed springcontact member from the strip l0 and form the leading end on theremainder of the strip.

A pair of centralizing devices 35-35 are provided in spaced relation toeach other along a predetermined center line passingthrough the axes ofthe punches Hi to accurately align the center line of the strip ID withthe axis of the punches l6. Each centralizing device comprises acylindrical member 36 mounted in a cylindrical aperture 31 in thestripper plate 22 for oscillation about its axis on said predeterminedcenter line. A pair of rollers 3939 engaging the upper surface of thedie l2 are mounted on a pair of downwardly projecting pins 40--40mounted on the cylindrical member 36 diametrically opposite andequi-distant from the axis of the member 36. The rollers 39 are spacedapart a distance slightly greater than the width of thestrip l and arepositioned on opposite sides of the strip for engagement with the edgeportions thereof.

A V-groove is formed in the upper portion of the cylindrical member 36providing a pair of inclined cam surfaces or elements 4343, which areadapted to be engaged by the edge 45 and angularly disposed cam surfaces45-46 of a cam member 48 yieldably mounted forreciprocation with the ramIS. The cam 48 is rectangular in cross section and is received in a.rectangular opening 49 in the retaining member I! and has an enlargedhead 50 receivable in a recess formed in the retainingimember I! and thepunch holder IS. A spring 52 yieldingly' urgesthe cam member 48downwardly into its normal position with the head 50 thereof seatedagainst the retainer member [1.

The V-groove in the cylindrical member 36 formed by the cam surfaces4343 is disposed obliquely with respect to a. vertical plane passingthrough the axis of the rollers 39-39 on the cylindrical member and theV-groove is normally disposed obliquely with respect to a planeperpendicular to the center line of the strip H). The edge 45 of the cammember 48 ispositioned in a plane perpendicular to the center line ofthe strip II] and is thus disposed obliquely with respect to thev-groove and on thedown stroke of the ram is adapted yieldingly toengagepoints on opposite cam surfaces 43-43 and impart to the member 36 alimited rotary movement sufficient to accomplish the centralizing of thestrip l0. To limit the cylindrical members 36 against excessive turningmovement when no strip II] isin position in the centralizing device themembers 36 are provided with laterally extending lugs 53-53 fitting inrecesses 54-54 in thestripper member 22 thereof,

In the operation of thed'evice after a contact spring member has beenpunched from the strip, the strip is advanced until the-leadingendthereof engages the stop 25, rollers 39 of each of thecentralizing-devices 35 are positioned on opposite sidesof-the stripwith no force acting through them on the strip so that the strip isloosely positioned"-therebetween. At a predetermined point in thedownward movement of the ram during the punching operation, the edges 45of the cam 48 engage the opposite inclined cam surfaces 43 of thecylindrical members 36 and impart rotary motionto the cylindricalmembers 36; This rotary motion serves to move the rollers 39 inarcuate-pathsin opposite directions toward the center line and intoengagement with the opposite edges of the-strip ID to accuratelycentralize the strip on the predetermined center line. The centralizingof the strip Ii! is completed before the punches l6 and 33 engage thestrip so that the stripisheld in-predetermined accurate alignment beforethe actual punching of the strip occurs.

What is claimed is:

1. A device for centralizing strip material on a predetermined centerline on a punch press having a reciprocatable ram comprising a supportfor said strip, a pair of centralizing means in spaced relation to eachother: on said-centerline,

and engageable with opposite walls as shown inFig. 1. The

one of said means comprising an oscillatable member mounted for rotationabout an axis on said center line, a pair of positioning members mountedon said oscillatable member diametrically opposed and equi-distant fromthe axis thereof and spaced apart a distance greater than the width, ofsaid strip for receiving said strip therebetween, and means foryieldably imparting rotation to said oscillatable member in response tothe down stroke of said ram to cause said positioning elements to movearcuately in opposite directions toward the center line to engage andcentralize said strip.

2. A device for centralizing strip stock on a predetermined center linein a punch press having a reciprocable ram comprising a stationarymember mounted above the path of movement of said strip and having apair of spaced apertures therein on said predetermined center line,cylindrical members mounted in said apertures in said member foroscillating movement about an axis on said center line, a pair ofrollers mounted on the lower side of each of said cylindrical membersdiametrically opposite and equidistant from the axis thereof and spacedapart a distance greater than the width of said strip for receiving saidstrip therebetween, a V-shaped cam groove formed transversely across theupper end of each of said cylindrical members, a nonrotatable cam memberaxially aligned with each of said cylindrical members and having a V-shaped end thereon, and means for yieldingly mounting said cam memberson said ram with the V-shaped ends thereof obliquely disposed about theaxes of said cylindrical members relative to the normal position of theV-grooves in said cylindrical members whereby at a predetermined pointin the down stroke of the ram the V-shaped endof the cam member engagesthe walls of the V -shaped groove and imparts rota-- tion to saidcylindrical member for centralizing said strip on said predeterminedcenter line.

3. A device for centralizing strip stock on a predetermined center lineof a punch press having a reciprocable ram comprising a support for saidstrip, a pair of centralizing means in spaced relation to each other onsaid center line, one of said means comprising an oscillatable membermounted for rotation about an axis on said center line, a pair ofpositioning members mounted on said oscillatable'member diametricallyopposite and equi-distant from the axis thereof and spaced apart adistance greater than the width of said strip for receiving said striptherebetween, a cam element on said oscillatable member, a cam membermovable relative to said oscillatable member and engageable with saidcam element to impart rotary movement to said oscillatable member, andmeans yieldably mounting said cam member for actuating movement inresponse to the downward movement of said ram whereby said cam memberacts to impart rotation to said oscillatable member to cause thepositioning elements thereon to move arcuately in opposite directionstoward the center line into engagement with the opposite edge of saidstrip to centralize said strip.

4. In a device for centralizing strip material on a predetermined centerline in a punch press having a reciprocable ram, the combination ofmeans for supporting the strip, an oscillatable member pivotally mountedfor turning movement about an axis on said center line, a pair ofrollers mounted on said oscillatable member diametrically opposite andequi-distant from said axis and spaced apart a distance greater than thewidth of said strip for receiving the strip therebetween, a cam portionon said oscillatable member, a cam member movable relative to saidoscillatable member and engageable with said cam portion thereon toimpart rotary movement to said oscillatable member, and means yieldablymounting said cam member for actuating movement in response to thedownward movement of said ram whereby said cam member acts to stresssaid oscillatable member for rotation about said axis to cause therollers thereon simultaneously to move in opposite directions toward thecenter line to centralize the strip therebetween.

5. A device for centralizing strip stock on a predetermined center lineof a punch press having a reciprocable ram comprising a support for saidstrip, a pair of centralizing means in spaced relation to each other onsaid center line, each of said means comprising an oscillatable membermounted for rotation about an axis on said center line, a pair ofpositioning elements diametrically opposite and equi-distant from theaxis thereof and spaced apart a distance greater than the Width of saidstrip of receiving said strip therebetween, a cam element on the upperportion of said oscillatable member, and a cam member yieldably mountedfor movement with the ram of said press for engaging said element on thedown stroke of said ram to yieldingly stress said oscillatable memberfor rotation, thereby to cause the positioning elements to move inopposite directions toward the center line into engagement with theedges of said strip to centralize said strip.

6. In a device for centralizing strip material on a predetermined centerline in a punch press having a reciprocable ram, the combination of asupporting means for supporting said strip in substantial alignment withsaid predetermined center line, a cylindrical member mounted for turningmovement about an axis of said center line, a pair of rollers mounted onsaid cylindrical member diametrically opposite and equi-distant fromsaid axis and spaced apart a distance greater than the width of saidstrip for receiving the strip therebetween, cam elements formed on saidcylindrical member, a cam member yieldably mounted on said ram formovement therewith for engaging said cam element on the down stroke ofsaid ram, thereby to yieldingly stress said cylindrical member forrotation to cause the rollers to move in opposite directions toward thecenter line into engagement with the edges of said strip to centralizesaid strip.

7. A device for centralizing strip stock on a predetermined center linein a punch press having a reciprocable ram comprising a support forsupporting said strip for movement along said center line, a pair ofcentralizing means in spaced relation to each other on said center line,each of said centralizin means comprising an oscillatable member mountedabove said support for rotation about an axis on said center line, apair of rollers mounted on said oscillatable member diametricallyopposite and equi-distant from the axis thereof and spaced apart adistance greater than the width of said strip for receiving said striptherebetween, a cam element on said oscillatable member, and a cammember yieldably mounted for movement with the ram of said press forengaging said cam element on the downstroke of said ram to yieldinglystress said osciliatable member for rotation thereby to cause therollers to move in opposite directions toward the center line intoengagement with the edges of said strip to centralize said strip,

ALEXANDER M. MACPHEAT.

No references cited.

